An alignment layer for liquid crystals used to align liquid crystal molecules in a certain direction may be applied in various fields. As the alignment layer, there is a photo-alignment layer, a surface of which is treated by light irradiation so as to align adjacent liquid crystal molecules. Conventionally, the photo-alignment layer may be manufactured by orientationally ordering photosensitive materials by irradiating a layer of the photosensitive material with light such as linearly-polarized light.
For example, Patent Documents 1 and 2 disclose devices for forming the photo-alignment layers.
To more effectively form the photo-alignment layer, it is necessary to irradiate an object to be irradiated with collimated light or nearly collimated light with uniform illumination. A technique of forming collimated light or nearly collimated light with uniform illumination may be widely applied in various fields including a process of forming the photo-alignment layer, and exposure for photolithography.